Field of the Invention
The present disclosure relates to a cartridge mountable to a main body of an image forming apparatus, such as a copier, a printer, or a facsimile machine.
Description of the Related Art
Image forming apparatuses that form an image on a recording material using an electrophotographic image forming method (electrophotographic process) are known. Examples of the image forming apparatuses include copiers and printers, such as laser beam printers and light-emitting diode (LED) printers. The examples also include facsimile machines, word processors, and multifunction peripherals (multifunction printers) combining these functions.
In an image forming apparatus using an electrophotographic image forming method, an electrophotographic photosensitive member (hereinafter simply referred to as “photosensitive member”) serving as an image bearing member is uniformly charged. Then, the charged photosensitive member is selectively exposed to light to form an electrostatic latent image on the photosensitive member. Next, a developer (toner) is supplied onto the electrostatic latent image on the photosensitive member to visualize it into a toner image. Then, the toner image formed on the photosensitive member is transferred onto a recording material, such as a recording sheet or plastic sheet. By applying heat and pressure to the toner image on the recording material, the toner image is thermally fused and fixed on the recording material.
An image forming apparatus, such as that described above, generally requires maintenance of various image formation processing units. To facilitate the maintenance of the various image formation processing units, a process cartridge is adopted, which is formed by combining a photosensitive member, a charging unit, a developing unit, and a cleaning unit into a frame. The process cartridge is detachably mounted to the main body of the image forming apparatus. With this process cartridge technique, an image forming apparatus with excellent usability can be provided.
In the process cartridge described above, a cleaning frame supports a photosensitive drum, a charging roller for charging the surface of the photosensitive drum, and a cleaning member that scrapes off developer remaining on the surface of the photosensitive drum. The photosensitive drum is rotatably supported by a bearing member on the cleaning frame.
In the process cartridge described above, the surface of the photosensitive drum is partly exposed from an opening in the frame. As a result, the user may touch the surface of the photosensitive drum. If the user touches the surface of the photosensitive drum, the resulting adhesion of finger oil or the like to the surface of the photosensitive drum may affect image quality.
To prevent the user from touching the surface of the photosensitive drum, the surface of the photosensitive drum may be covered with a drum cover. The drum cover has the function of protecting the surface of the photosensitive drum from light, dust, and user's touch. To further reduce the risk of the user accidentally touching the surface of the photosensitive drum, Japanese Patent Laid-Open No. 2000-029368 discloses a technique in which a message warning the user not to touch the surface of a photosensitive drum is printed on a flexible sheet member jutting from one edge of an opening in a frame.
Japanese Patent Laid-Open No. 08-248842 and No. 2008-176157 disclose techniques in which the life of an image bearing member, the lives of components of an image forming unit, and apparatus information including various lives, operating conditions, and environments of an image forming apparatus, are displayed as a toner image on the image bearing member by an image forming device. However, the techniques disclosed in Japanese Patent Laid-Open No. 08-248842 and No. 2008-176157 are not designed to prevent the user from touching the surface of a photosensitive drum.
The process cartridge may be mounted to the main body of the image forming apparatus after removal of the drum cover covering the surface of the photosensitive drum. When the process cartridge is mounted on the main body of the image forming apparatus, the surface of the photosensitive drum is partly exposed from the opening in the frame. Therefore, after removal of the drum cover, the user may touch the surface of the photosensitive drum before the process cartridge is inserted into the main body of the image forming apparatus.
With a recent increase in the life of process cartridges, a technique has been proposed in which a drum cartridge including a photosensitive drum and a developing cartridge including a developing device are configured as separate components. The drum cartridge and the developing cartridge can thus be replaced separately. This configuration increases the surface area of the photosensitive drum exposed from the opening in the frame. Accordingly, it is required to provide a configuration that prevents the user from touching the surface of the photosensitive drum.